Visual interpreter for a simple lisp-style programming language.
(print "hello, world!");
(set "x" 10);
(set "t" 1);
(set "i" 1);
(while (! (= $i (+ $x 1)))
(set "t" (* $t $i))
(set "i" (+ $i 1)));
(print "factorial of " $x " is " $t);